class_docstr: A class to open and interact with fits files from SDSS
  
  Parameters
  ----------
  buf : string or file buffer (optional)
      file path, buffer, or url of SDSS spectra fits file
      if None, then initialize an empty instance.
  
  Notes
  -----
  This class only provides access to a subset of the information available
  in the sdss spectra fits file.  The raw fits data can be accessed using
  the fits object directly.  This can be found in the attribute
  ``hdulist``.  For details, please refer to the data description:
  http://www.sdss.org/dr7/dm/flatFiles/spSpec.html
code: def _initialize(self, hdulist):
      data = hdulist[0].data
  
      self.name = hdulist[0].header["NAME"]
      self.spec_cln = hdulist[0].header["SPEC_CLN"]
      self.coeff0 = hdulist[0].header["COEFF0"]
      self.coeff1 = hdulist[0].header["COEFF1"]
      self.z = hdulist[0].header["Z"]
      self.zerr = hdulist[0].header["Z_ERR"]
      self.zconf = hdulist[0].header["Z_CONF"]
  
      self.spectrum = data[0]
      self.spectrum_cont = data[1]
      self.error = data[2]
      self.mask = data[3]
      self.large_err = self.error.max() * 2
      self.hdulist = hdulist
  
imports: import gc
  import numpy
  from scipy.ndimage import gaussian_filter1d, uniform_filter1d
  from scipy import interpolate
  from .None import download_with_progress_bar
label_desc: Use image node_id 4 for calling the SDSSfits obj's underlying member method code with example usage: obj._initialize(hdulist) without return types